Currently, bus technologies in industrial fields are widely used in situations where, for example, dangerous explosive gas and dust environments are present, such as petrochemical, metallurgy, coal, natural gas, and pharmaceutical fields, etc, so as to implement digitalization and networking of sensor nodes. In such field bus technologies, a CAN bus has higher communication reliability and error tolerance compared to known RS232/RS485/RS422.
The CAN bus may be applied in dangerous flammable and explosive situations. At least some nodes in the CAN bus have explosion proof functions. In an implementation of CAN bus explosion proof nodes in a current explosion proof environment, an explosion isolation type method, a pouring encapsulation type method, and a “n”-type method are primarily employed. The first two methods can be complex in manufacturing, difficult to mount, and large in structure size so that the nodes cannot be miniaturized. The “n”-type explosion proof method can merely be applied in a Class II environment but cannot be applied in a Class I environment so as to limit its scope of usage.